Characterizing the Myoarchitecture of the Supraspinatus and Infraspinatus Muscles With MRI Using Diffusion Tensor...

Area of Science:

• Biomedical Engineering
• Musculoskeletal Imaging
• Quantitative Anatomy

Background:

• Societal costs of shoulder disabilities are rising.
• Early detection of rotator cuff (RC) muscle microstructure changes may improve surgical planning.
• Ultrasound assessment of elevation angle (E1A) and pennation angle (PA) lacks repeatability.

Purpose of the Study:

• To develop a repeatable framework for quantifying myocyte angulation in RC muscles using diffusion tensor imaging (DTI).

Main Methods:

• Prospective study involving six healthy volunteers.
• Diffusion tensor imaging (DTI) was used to scan infraspinatus muscle (ISPM) and supraspinatus muscle (SSPM).
• Myocyte angulation (E1A and PA) was quantified across muscle depth using polynomial and sigmoid fits.

Main Results:

• The DTI framework demonstrated repeatability for E1A and PA in both ISPM and SSPM within volunteers (error <10%).
• Intra-repeatability of the radial axis measurement was achieved (error <5%).
• Distinct myocyte angulation patterns were observed in ISPM and SSPM across depth.

Conclusions:

• The proposed DTI framework provides repeatable quantification of E1A and PA in RC muscles.
• This method allows for the quantification of myocyte angulation variations across volunteers, aiding in understanding muscle microstructure.